Once Steve Kazee and Cristin Milioti portray the Guy and the Girl in this musical at the New York Theater Workshop, inspired by the movie of the same title.Credit
Sara Krulwich/The New York Times

Charm is fragile. What’s enchanting in one context, subjected to stress, exaggeration or self-consciousness, can seem soppy or strident in another.

That’s the big problem faced by the talented creators of “Once,” the gently appealing new musical that opened on Tuesday night at the New York Theater Workshop, and it’s one they’ve only partly resolved. For if ever there was an example of delicately balanced charm, poised to go flat or splat, it is the 2006 Irish movie that inspired this show.

Written and directed by John Carney, the movie “Once” was a low-budget, low-key venture in which a Dublin guy and girl — identified as only Guy and Girl — meet cute (he fixes her vacuum cleaner), make music and almost make love. Both composers (who play songs by the musicians who portray them, Glen Hansard and Marketa Irglova), they achieve creative consummation by making a most promising demo tape. A hit at the Sundance Film Festival, “Once” is now a cherished cult favorite, a sort of “Brief Encounter” for the scruffy folk-pop set of the 21st century.

Dangerous clichés are always lurking just beneath the surface of this film, ready to pop up like emoticons in a text message. Only the steady, understated naturalness of the performances, much of which were improvised, keeps the movie from coming down with that bad case of the cutes that often afflicts rom-coms.

Musicals — especially those with aspirations of making it on Broadway, where the stage version of “Once” is now headed — are a different animal from films, even films that spend half their time singing. Subtlety, for instance, has never been considered an asset in musicals. Whimsy, on the other hand, is often allowed to run wild.

In translating “Once” into three dimensions, the playwright Enda Walsh (whose superb “Misterman” is currently at St. Ann’s Warehouse in Brooklyn) and the director John Tiffany (“Black Watch”) haven’t steered clear of what were probably inevitable excesses. The script is now steeped in wise and folksy observations about committing to love and taking chances, most of which are given solemn and thickly accented utterance by Girl (played by Cristin Milioti), who is Czech.

Guy, played by Steve Kazee, has been transformed from a shaggy nerd into a figure of leading-man handsomeness, while Girl has turned into a full-fledged version of what she only threatened to be in the film: a kooky, life-affirming waif who is meant to be irresistible. And supporting characters who were allowed scant screen time have been scaled up to become the sort of winsomely wacky background figures you find in fluffy screen fare starring Julia Roberts or Kate Hudson.

But a merciful reversal occurs when “Once” breaks into music, which is often. Characters become less adorably overwrought and more genuinely conflicted, with distinctive personalities instead of standard-issue ones. The songs (written by Mr. Hansard and Ms. Irglova) soar with rough-edged, sweet-and-sad ambivalence that is seldom visited in contemporary American musicals. (And yes, the score still includes “Falling Slowly,” which won the Academy Award for best song.)

The subliminal choreography, by Steven Hoggett, has a fractured individuality. Without overstating itself, it looks as weird as these people feel they are inside. In song, “Once” delivers an original interior view of its characters. And some of the numbers are as fresh and unexpected as anything seen in New York since “Spring Awakening.”

As anyone knows who saw “Black Watch,” a collage portrait of a Scottish Army regiment in Iraq, Mr. Tiffany and Mr. Hoggett are masters of surprising stagecraft. “Once,” designed by the inventive Bob Crowley, turns its stage into a meticulously authentic-looking pub, the kind of place where people gather not so much to forget their sorrows as to expatiate on them, in drink and in song.

Photo

Steve Kazee, standing at the microphone, with other members of the “Once” cast.Credit
Sara Krulwich/The New York Times

The production has a prologue of sorts in which the audience is invited onstage to mingle with cast members, who play their own instruments and are (quite satisfyingly) their own orchestra. Classic drinking numbers are performed casually but spiritedly, setting up a world in which the wall between song and speech is porous.

What follows doesn’t always sustain that aura of permeability and spontaneity. Once you’ve accepted that a fellow as good-looking as Mr. Kazee is a nebbish, Guy is a touching presence, whose self-doubt is as evident as his singing talent. But all the other characters have been rewritten into states of high, and rather generic, idiosyncrasy. (The generic part surprises me, since that is one adjective I would never have applied to Mr. Walsh as a playwright.)

Billy (Paul Whitty), a piano store owner, is a lovable blowhard who regularly throws his back out demonstrating martial arts moves. The bank manager (Andy Taylor) who gives Girl and Guy a loan is built up into a twanging, semi-closeted country-and-western fan.

Girl’s mother, Baruska (Anne L. Nathan), is a folkloric bulldozer of advice. And Girl’s Czech roommates (Will Connolly, Elizabeth A. Davis and Lucas Papaelias) have all been assigned distinguishing eccentricities, which they wear like oversize lapel buttons. Mr. Papaelias’s character, a natural-born mimic, is the only one I truly enjoyed, though all the performers — who also include Claire Candela, David Patrick Kelly, Erikka Walsh and J. Michael Zygo — work honorably within the broad outlines that have been drawn for them.

But it’s with Girl that I had the most problems. Not with Ms. Milioti, who gives what is, under the circumstances, a restrained performance, but with her character as a catalyst.

Guy, who begins the show suicidal, asks her at one point if she isn’t an angel who’s been sent to put his life in order. And that really is her function here, far too conspicuously.

She has a habit of saying inspirational things that make you want to hightail it to the nearest bar (though not the one onstage). “These songs need to be sung for you, for me, for anyone who has lost a love and still wants to love,” she says to Guy. (If that was in the movie, it kindly passed me by.) She also tells him that he is “wasting your life because you’re frightened of it.”

But when she sings, in a haunted voice that brings to mind the Bjork of the movie “Dancer in the Dark,” she becomes a fully realized human being, both mysterious and accessible. In the first act, Girl has a number in which she puts words to music written by Guy that I can’t stop thinking about.

Ms. Milioti performs the song (with Ms. Davis and Ms. Walsh) using ritualized gestures that suggest a soul quietly wrestling with its own sadness, and I thought of the ethereally tormented women painted by Edvard Munch. Unlike most musicals, “Once” is most at home in the depths; it’s on the surface that it feels out of its element.

ONCE

Book by Enda Walsh; music and lyrics by Glen Hansard and Marketa Irglova; based on the motion picture written and directed by John Carney; directed by John Tiffany; movement by Steven Hoggett; music supervisor/orchestrations by Martin Lowe; sets and costumes by Bob Crowley; lighting by Natasha Katz; sound by Clive Goodwin; dialect coach, Stephen Gabis; vocal supervisor, Liz Caplan Vocal Studios. Presented by the New York Theater Workshop, James C. Nicola, artistic director. At the New York Theater Workshop, 79 East Fourth Street, East Village; (212) 279-4200; ticketcentral.com. Through Jan. 15. Running time: 2 hours 25 minutes.

Once

CreditsBook by Enda Walsh, music and lyrics by Glen Hansard and Marketa Irglova, based on the motion picture written and directed by John Carney, directed by John Tiffany, movement by Steven Hoggett, musical supervision by Martin Lowe, set and costume design by Bob Crowley, lighting design by Natasha Katz, sound design by Clive Goodwin

A version of this review appears in print on December 7, 2011, on page C1 of the New York edition with the headline: A Love Affair With Music, Maybe With Each Other. Order Reprints|Today's Paper|Subscribe